Humans (人間, Ningen^?), falling under the category of Primates (霊長, Reichou^?), are the most prevalent species on the planet. The term is referring to mankind's current evolutionary stage as a species rather than mankind as a group. The collective will of humanity is represented by Alaya, and it is at odds with the natural forces of the planet. During the Age of Gods, humanity was much closer to the root and the gods, but that connection has dwindled over the millennia. The world was very antagonistic towards humans, so much that even someone like Gilgamesh was unable to needlessly kill people. Being closer to the origin made the power of Alaya more concentrated, and it increased the weight of each human soul in comparison to modern humans. Humanity eventually develops to the point where it can outlive the planet itself in the world of Notes, and the Humans evolve dramatically.

Humans can be born with innate abilities such as extrasensory perception and other abnormal powers called ESP (超能力, Chounouryoku^?). They are normally functions that aren't involved in the operation of the organisms called humans, which are the circuits that cause "supernatural phenomena" to occur. Compared to thaumaturgy, which can be trained over time, inherent ability is absolutely necessary to use ESP. Those who have these abnormal lines can cause supernatural phenomenon to happen as if they were simply breathing. Those experiencing it find it to be normal, so they only realize the abnormality of themselves for the first time when the common sense of others point this out to them.

It is possible for humans to have offspring with supernatural species, resulting in the birth of Mixed-Bloods (混血, Konketsu^?). Such hybrids include offspring between humans and members of the Oni Kind, such as the Tohno and Kishima clans, and others include the half incubus Merlin, the descendant of a half succubus Natalia Kaminski and Altrouge Brunestud, the offspring between a Dead Apostle and a True Ancestor. Such beings are seen as a distortion that needs to be exterminated in Japan, but they make for troublesome targets for the Demon Hunters. They are immune to the Edict of Binding of Houjutsu, and it is impossible to match their supernatural powers with just a human body.